Doc crypto #465

Job	Run time
afl-build	4m 55s
all-features	1m 32s
audit	9s
build (linux)	1m 56s
build (macos)	2m 39s
clippy	3m 52s
fmt	7s
build (windows)	4m 50s
long-tests	4m 13s
publish-dry-run	4s
test-bindings-c-cpp-linux	1m 14s
test-bindings-c-cpp-windows (Debug-c, x86_64-pc-windows-msvc)	1m 44s
test-bindings-c-cpp-windows (Debug-c, i686-pc-windows-msvc)	1m 40s
test-bindings-c-cpp-windows (Release-c, x86_64-pc-windows-msvc)	1m 12s
test-bindings-c-cpp-windows (Release-c, i686-pc-windows-msvc)	1m 18s
test-bindings-c-cpp-windows (Debug-cpp, x86_64-pc-windows-msvc)	1m 33s
test-bindings-c-cpp-windows (Debug-cpp, i686-pc-windows-msvc)	1m 34s
test-bindings-c-cpp-windows (Release-cpp, x86_64-pc-windows-msvc)	1m 11s
test-bindings-c-cpp-windows (Release-cpp, i686-pc-windows-msvc)	1m 8s
	36m 51s

Provide feedback